CN117924492A

CN117924492A - Humanized CD25 monoclonal antibody and preparation method and application thereof

Info

Publication number: CN117924492A
Application number: CN202311815860.6A
Authority: CN
Inventors: 刘鸿君; 王倩; 刘勇; 李忠鹏; 王福润; 卢南南
Original assignee: Huizhi Heyuan Biotechnology Suzhou Co ltd
Current assignee: Huizhi Heyuan Biotechnology Suzhou Co ltd
Priority date: 2023-12-27
Filing date: 2023-12-27
Publication date: 2024-04-26

Abstract

The invention discloses a humanized CD25 monoclonal antibody and a preparation method and application thereof, the amino acid sequences of heavy chain complementarity determining regions CDR-H1, CDR-H2 and CDR-H3 of the antibody or antigen binding fragment thereof are shown as SEQ ID NO.1, and the amino acid sequences of light chain complementarity determining regions CDR-L1, CDR-L2 and CDR-L3 of the antibody or antigen binding fragment thereof are shown as SEQ ID NO. 2. The humanized CD25 antibody can specifically identify and combine the humanized CD25 protein and the CD25+ cells, has higher affinity, can be used for flow cytometry detection of the CD25+ cells, and has wide application prospects in detection of the humanized CD25 protein and the CD25+ cells.

Description

Humanized CD25 monoclonal antibody and preparation method and application thereof

Technical Field

The invention relates to the field of antibodies, in particular to a human CD25 monoclonal antibody, a preparation method and application thereof.

Background

CD25 is the alpha chain of the IL-2 receptor, and upon binding to IL-2 promotes heterodimerization of CD122 (IL 2R beta) and CD132 (IL 2R gamma), ultimately forming tetramers (IL 2R alpha/beta/gamma and IL-2), and triggering the JAK/STAT5, PI 3K/Akt/and MAPK signaling pathways, playing an important role in cell growth, survival, differentiation and immunization.

CD25 is highly expressed in most regulatory T cells (Tregs), a marker of Tregs. The Treg cells have remarkable immunosuppressive effect, can defend autoimmune diseases of human bodies, can promote tumor cells to generate immune escape, indirectly accelerate proliferation of the tumor cells, and the depletion of the Treg cells directly promotes tumor regression, and CD25 is a potential target for realizing Treg depletion and can be used for developing a novel immunotherapy method.

Monoclonal antibody technology was invented by the uk scientist Milstein and Kohler in 1975, the principle of which is: b lymphocytes are capable of producing antibodies, but are unable to divide indefinitely in vitro; although tumor cells can be subjected to infinite passage in vitro, antibodies cannot be produced, the hybridoma cells obtained by fusing the two cells have the characteristics of two parent cells, and the monoclonal antibody can be obtained through animal immunization, cell fusion, cell screening, cloning, characteristic identification and the like, so that specific single antigen epitopes can be identified, and the monoclonal antibody has high specificity.

For human CD25, there is currently a lack of human CD25 antibodies that can bind to them with high efficiency and are suitable for detection by flow cytometry and the like.

Disclosure of Invention

The invention aims to provide a humanized CD25 monoclonal antibody, a preparation method and application thereof, so as to solve the problems in the background technology.

In order to achieve the above purpose, the present invention provides the following technical solutions:

The invention provides an antibody or antigen binding fragment thereof, the amino acid sequences of heavy chain complementarity determining regions CDR-H1, CDR-H2 and CDR-H3 of the antibody or antigen binding fragment thereof are shown in SEQ ID NO.1, and the amino acid sequences of light chain complementarity determining regions CDR-L1, CDR-L2 and CDR-L3 are shown in SEQ ID NO. 2.

The antibody or the antigen binding fragment thereof can specifically recognize and bind to the human CD25 protein and cells expressing the human CD25 protein (CD25+ cells), and has higher affinity.

Preferably, the amino acid sequence of the heavy chain variable region of the antibody or antigen binding fragment thereof is shown as SEQ ID NO.3 or has at least 80% similarity to the amino acid sequence shown as SEQ ID NO.3, and the amino acid sequence of the light chain variable region is shown as SEQ ID NO.4 or has at least 80% similarity to the amino acid sequence shown as SEQ ID NO. 4.

In some embodiments of the invention, the amino acid sequence of the heavy chain variable region of the antibody or antigen binding fragment thereof is shown in SEQ ID NO.3 and the amino acid sequence of the light chain variable region is shown in SEQ ID NO. 4.

In the case of the heavy chain complementarity determining regions CDR-H1, CDR-H2, CDR-H3 and light chain complementarity determining regions CDR-L1, CDR-L2, CDR-L3 described above, the amino acid sequence of the heavy chain variable region is an antibody or antigen binding fragment thereof corresponding to an amino acid sequence having at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 99.5% sequence similarity to the amino acid sequence shown as SEQ ID No.3, and the amino acid sequence of the light chain variable region is an amino acid sequence having at least 80%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99.5% sequence similarity to the amino acid sequence shown as shown in SEQ ID No. 4.

The antibody or antigen-binding fragment thereof described above is any one selected from the group consisting of monoclonal antibodies, fab ', F (ab') 2, fd, fv, dAb, complementarity determining region fragments, and single chain antibodies.

Among them, monoclonal antibodies include animal-derived antibodies (e.g., murine antibodies), chimeric antibodies, humanized antibodies, and the like.

The present invention provides bispecific or multispecific antibodies comprising an antibody or antigen-binding fragment thereof described above.

The present invention provides a nucleic acid molecule encoding an antibody or antigen binding fragment thereof as described above.

Based on the amino acid sequence and codon regularity of the above-described antibodies or antigen-binding fragments thereof, one skilled in the art can obtain the nucleotide sequence of a nucleic acid molecule encoding the above-described antibodies or antigen-binding fragments thereof. Because of the degeneracy of the codons, the nucleotide sequences of the nucleic acid molecules encoding the antibodies or antigen binding fragments thereof are not unique, and all nucleic acid molecules capable of encoding the antibodies or antigen binding fragments thereof are within the scope of the invention.

The present invention provides a biological material comprising the nucleic acid molecule described above, which biological material is an expression cassette, a vector or a host cell.

The expression cassette can be obtained by operably linking the nucleic acid molecules described above with regulatory elements such as promoters, terminators, and the like.

The vectors described above include, but are not limited to, plasmid vectors, viral vectors, and the like.

The host cells described above include microbial cells or animal cells. Wherein the microbial cells include, but are not limited to, E.coli, yeast, etc., and the animal cells include, but are not limited to, CHO cells, 293T cells, etc.

The invention provides an antibody conjugate, which is obtained by coupling the antibody or the antigen binding fragment thereof or the bispecific antibody or the multispecific antibody with a label or a protein.

Preferably, the label is selected from one or more of chemiluminescent dye label, enzyme label, biotin label, fluorescent dye label, colloidal gold label, and radioactive label.

The antibodies or antigen-binding fragments thereof provided herein can be prepared by methods conventional in the art, including: chemical synthesis, host expression, and the like.

The present invention provides a method of preparing an antibody or antigen-binding fragment thereof as described above, the method comprising: culturing a host cell capable of expressing the antibody or antigen-binding fragment thereof, and isolating the antibody or antigen-binding fragment thereof.

The present invention provides the use of any of the antibodies or antigen binding fragments thereof or the bispecific or multispecific antibodies or the nucleic acid molecules or the biological material or the antibody conjugates described above:

(1) Use in the preparation of a product for detecting the presence or level of a human CD25 protein or a cell expressing a human CD25 protein in a sample;

(2) Use in detecting the presence or level of a CD25 protein of human origin in a sample;

(3) Use in detecting the presence or level of cells expressing a human CD25 protein in a sample;

in the above (1), the product may be a detection reagent or a kit.

In the above (1), (2) and (3), the sample may be a sample derived from a living human or animal (including blood or the like), or may be a sample derived from a non-living human or animal such as cells or cell culture medium cultured in vitro.

For the above (2) and (3), detection for the purpose of diagnosis and treatment of non-disease is preferable.

In the applications described in (1), (2) and (3), the method for detecting an antibody or an antigen-binding fragment thereof provided by the present invention is preferably flow cytometry.

The present invention provides a product comprising an antibody or antigen binding fragment thereof as described above, or comprising said bispecific or multispecific antibody, or comprising said antibody conjugate; the product is a detection reagent or a pharmaceutical composition.

The invention has the beneficial effects that: the humanized CD25 antibody provided by the invention can specifically identify and combine the humanized CD25 protein and CD25+ cells, has higher affinity, can be used for detection of flow cytometry of the CD25+ cells and the like, has higher sensitivity and specificity, and has wide application prospects in detection of the humanized CD25 protein and the CD25+ cells.

Drawings

FIG. 1 shows the results of hCD25 monoclonal antibodies used in flow cytometry in example two of the present invention, wherein A, B, C, D is the results of A, B, C, D tubes, respectively.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The invention provides a technical scheme that: human CD25 monoclonal antibody and its preparation process and application;

Specifically, the acquisition of the humanized CD25 monoclonal antibody comprises animal immunization (taking recombinant hCD25 protein as antigen), cell fusion, screening and cloning of positive hybridoma cells, ascites purification and flow cytometry verification. The humanized CD25 monoclonal antibody provided by the invention can effectively combine hCD25 and CD25+ cells, has stable performance, and can be used for detecting CD25+ cells by flow cytometry.

In the invention, positive hybridoma cells are screened through recombinant hCD25 protein, and then verified through flow cytometry, so that the monoclonal antibody can effectively identify natural hCD25 protein, the problem of later large-scale screening is avoided, the research and development period of the monoclonal antibody is shortened, and the operation is simple;

The reagents used in the following examples and their formulations are shown in the following table:

Example 1

Acquisition of human CD25 monoclonal antibody:

the hCD25 monoclonal antibody provided by the invention is obtained by the following steps:

step one, recombinant hCD25 expression and purification:

HEK293 cells are transfected with hCD25 recombinant plasmid 100mL,5% CO2 constant temperature shaking table, 37 ℃ and 120rpm constant temperature shaking culture for 6d, stop culture, place cell sap at 1000rpm, centrifuge for 5min, suck supernatant, pass through 0.45um filter membrane, adjust supernatant pH to 7.4 with 1M Tris-HCl (pH8.8), turn on pure instrument, wash chromatography column with 10mL1 XPBS, start loading, loading flow rate is 1mL/min, wash chromatography column with 10mL1 XPBS, elute and collect hCD25, protein quantification instrument measure concentration, combine high concentration hCD25 solutions, place purified hCD4 solution at 1 XPBS, 4 ℃ dialysis overnight, collect hCD25 solution, and quantitate with BCA protein quantification kit.

Step two, animal immunization:

The purified recombinant hCD25 was diluted to 0.4mg/mL, and mixed with water-soluble rapid adjuvant (Boolon Quick antibody mouse w) in equal volume, and 6 female Balb/c mice 6 weeks old were inoculated in multiple spots on leg muscle at an antigen dose of 20 μg/mouse. After 21d, the injection was again performed, and the amount of immunity was the same as that of the first time. 3d before cell fusion, the recombinant hCD25 without adjuvant is injected into the abdominal cavity for immune impact, and then cell fusion is carried out.

Step three, establishing an indirect ELISA method of recombinant hCD 25:

Recombinant hCD25 was diluted to 1,5, 10, 15, 20. Mu.g/mL with carbonate buffer (pH 9.6), 100. Mu.L/well, incubated at 37℃for 1h, overnight at 4℃for a spin-drying of the coating, PBST wash 3 times, 5% skim milk blocking solution was added, 250. Mu.L/well, incubated at 37℃for 1h, with PBST wash 3 times, 5% skim milk was used to dilute negative and positive serum 1:1000, 1:2000, 1:4000, 1:8000, 1:16000, 1:32000, 1:64000 and 1:128000, 100. Mu.L/well, with PBST wash 3 times, goat anti-mouse IgG-HRP was diluted 1:10000 times with skim milk, 100. Mu.L/well, 37℃for 0.5h, PBST wash 4 times, each well was added with freshly prepared TMB color developing solution, 100. Mu.L/well, at room temperature for 10min, 1M H2SO4 was added, 50. Mu.L/well was stopped, and the concentration of the recombinant protein was determined by the dilution experiments on the serum and the dilution, the serum was determined by the dilution experiments, the optimal concentration of the positive and the serum was carried out on the dilution, the serum dilution.

Step four, preparation of sp2/0 myeloma cells:

Taking out sp2/0 cells in a liquid nitrogen tank, putting into 37 ℃ water for melting, centrifuging at 1000rpm for 5min, discarding supernatant, re-suspending with DMEM complete culture solution, transferring into a cell bottle, and culturing in a saturated humidity incubator at 37 ℃ and 5% CO 2. The sp2/0 cells with uniform cell morphology, clear boundary and good growth state are taken in the day of fusion, the culture solution is discarded, the culture solution is washed for 2 times, then 20mL of the DMEM culture solution is used for resuspension of the cells, and then the cells are counted and placed at 4 ℃ for standby.

Step five, preparing feeder cells:

Before fusion, selecting 2 non-immunized 10-week-old Kunming female mice, killing cervical dislocation, soaking in 75% alcohol for 5min, sterilizing, cutting off abdominal skin under aseptic condition, and fully exposing abdomen; the peritoneum was lifted with forceps, 8mL of HAT culture solution was injected into the abdominal cavity with a syringe, the abdomen was gently pressed with an alcoholic cotton ball, finally the culture solution in the abdominal cavity was aspirated with a syringe, the cells were counted, the number of cells was adjusted to 2X 105 cells/mL by resuspension with HAT culture solution, 100. Mu.L/well was added to 96-well plates, and the plates were placed in a saturated humidity incubator at 37℃with 5% CO2 overnight, and whether contamination was observed.

Step six, spleen cell preparation:

The titers of the serum of immunized mice were determined by indirect ELISA, and when the hCD25 antibody titers in the serum reached 16000, recombinant hCD25 was boosted once. After 3d, the mice were collected from their eyeballs, and the blood was centrifuged at 37℃for 0.5h,4℃for 1h,4000rpm for 5min, and the separated serum was used as positive serum. Mice were sacrificed, and after 5min of sterilization by 75% alcohol, spleens were removed under aseptic conditions and ground on a 70 μm cell sieve. The obtained spleen cells were washed 2 times with DMEM medium (1000 rpm, centrifugation for 8 min), and then the cells were suspended in 20mL of DMEM medium and counted.

Step seven, cell fusion:

Mixing the prepared sp2/0 myeloma cells and spleen cells in a ratio of 1:5-1:10, placing the mixture into a 50mL centrifuge tube, washing 3 times with DMEM culture solution, centrifuging at 1000rpm for 8min, sucking the supernatant after the last centrifugation, tapping the bottom of the centrifuge tube with fingers to loosen the cells, placing the centrifuge tube into a water bath at 37 ℃, sucking 1mL of preheated PEG1450 (Sigma) at 37 ℃ at a constant speed, adding the centrifuge tube while gently stirring, adding the mixture completely within 1min, standing for 1min, slowly adding 30mL of DMEM culture solution, adding 1mL of the mixture for 1min, adding 2min, adding 3mL of the mixture, adding 5mL of the mixture, adding 7mL of the mixture, adding all 5min, centrifuging at 1000rpm for 8min, discarding the supernatant, closing the cells with the weight suspension min, performing a gentle action, preventing the blowing off of the freshly fused cells, adding 60-100mL of HAT culture solution, starting to spread 96-hole cell culture plates, placing the cell culture plates into a saturated humidity incubator at 37 ℃ for 5% CO2, culturing at 3min, slowly adding 30mL of the mixture, and replacing half HT culture solution after half a volume of 10d after the fusion culture solution is replaced.

Step eight, establishing hCD25 hybridoma cell strains:

Screening of positive hybridoma cells: and 10d, HT culture solution is used instead, and detection is carried out when the hybridoma cells grow to 1/4 of the bottom of the hole. Coating an ELISA plate with recombinant hCD25 according to the optimal coating concentration, taking hybridoma cell culture supernatant after 2d of liquid exchange, reacting with the recombinant hCD25, taking sp2/0 cell culture supernatant as negative control, taking positive mouse serum as positive control, and selecting hybridoma cell holes reacted with the recombinant hCD25 as positive cell strains for next subcloning.

Subcloning cells: feeder cells were prepared according to the fourth step, and 96-well plates were plated on the feeder cells obtained after washing the abdominal cavity of the mice with HT nutrient solution, 100. Mu.L/well, and the 96-well plates were cultured overnight in a 5% CO2, saturated humidity incubator at 37 ℃. The cells in the hybridoma cell wells detected as positive were blown up and mixed uniformly, 10. Mu.L of cells were taken, the cells were counted after 10-fold dilution, 100 cells were calculated from the corresponding wells and added to 10mL of HT medium, and the cells were inoculated into 96-well cell culture plates plated with feeder cells at 100. Mu.L/well, i.e., about 1 cell per well. The cell plates were incubated at 37℃in a 5% CO2 saturated humidity incubator. After 4d, observing the clone number of each hole, when 7-10d cells grow to 1/4 hole bottom, performing ELISA detection, and taking 2 times of monoclonal holes positive in detection for subcloning. After 3 subcloning until the detection positive rate of all cloned cell holes is 100%, the hybridoma cell strain capable of stably secreting monoclonal antibodies can be determined.

Cryopreservation and resuscitation of hCD25 hybridoma cells: and (3) performing amplification culture on the final clone which is positive and is observed to be a single clone hole under a microscope, blowing off cells in the hole into a 6-hole plate, and transferring the cells into a 50mL cell bottle for culture after the cells in the 6-hole plate are full. After the cells grow to 80% -90%, subculturing, and simultaneously freezing hybridoma cell strains, wherein each strain is frozen for 3 tubes. Taking cells with good growth log phase, blowing off and mixing uniformly, centrifuging at 1000rpm for 8min, discarding supernatant, re-suspending the cells with frozen solution to make the number of the cells reach 1×106 cells/mL, transferring into a frozen tube, transferring into a program cooling box at-70 ℃ for overnight, and transferring into liquid nitrogen for storage the next day.

Preparing ascites: 10-week-old Balb/c female mice were intraperitoneally injected with 0.5mL of liquid paraffin. After 7d, the abdominal cavity was inoculated with 1X 106 hybridoma cells per cell. Before inoculation, hybridoma cells were washed twice with DMEM medium at a concentration of 1×107 cells/mL, and 0.1mL of the cell suspension was taken and injected into the abdominal cavity of the mice. After 7d, ascites can be generated, and the ascites can be collected by suction of a syringe. The collected ascites was centrifuged at 3000rpm for 5min, and the supernatant was collected.

Step nine, purifying the hCD25 monoclonal antibody:

The ascites 12000rpm was centrifuged for 5min, the supernatant was collected, the precipitate was discarded, the centrifuged ascites was filtered with a 0.22 μm filter membrane, the Protein A column was washed with 10 times the filler volume of PBS at a flow rate of 1mL/min, the filtered ascites was added to the chromatography column at a flow rate of 1mL/min, the Protein A column was washed with 10 times the filler volume of PBS at a flow rate of 1mL/min, eluted with pH3.0, 0.1M glycine-HCl at a flow rate of 1mL/min, the eluate was collected with a 1.5mL centrifuge tube, 0.5mL was collected per tube, 12 tubes were continuously collected, 20. Mu.L of 1M Tris-HCl (pH 8.8) was added per tube for neutralization after completion of the collection, and the purified monoclonal antibody was dialyzed against PBS, dialyzed overnight at 4℃and quantified with BCA quantification kit, the concentration was adjusted to 1mg/mL.

Sequencing the hCD25 monoclonal antibody, and the sequencing result shows that the amino acid sequences of the heavy chain complementarity determining regions CDR-H1, CDR-H2 and CDR-H3 of the hCD25 monoclonal antibody are shown as SEQ ID NO.1, the amino acid sequences of the light chain complementarity determining regions CDR-L1, CDR-L2 and CDR-L3 are shown as SEQ ID NO.2, the amino acid sequence of the heavy chain variable region is shown as SEQ ID NO.3, and the amino acid sequence of the light chain variable region is shown as SEQ ID NO. 4.

HCD25 monoclonal antibody titer detection: recombinant hCD25 was diluted to 1. Mu.g/mL with carbonate buffer (pH 9.6), incubated at 37℃for 1h, overnight at 4℃to spin-dry the coating solution, PBST washed 3 times, 5% skim milk blocking solution was added, 250. Mu.L/well, incubated at 37℃for 1h with PBST washed 3 times, 1mg/mL hCD25 monoclonal antibody and 1mg/mL hCD14 monoclonal antibody were diluted with 5% skim milk 1:1000, 1:2000, 1:4000, 1:8000, 1:16000, 1:32000, 1:64000 and 1:128000, 100. Mu.L/well incubated at 37℃for 1h, PBST washed 3 times with 1:10000 times of skim milk, 100. Mu.L/well incubated at 37℃for 0.5h, PBST washed 4 times, each well was added with fresh TMB color development solution, 100. Mu.L/well was developed at room temperature for 10min, 1:32000, 1:64000 and 1:128000, and the SOOD was stopped by measuring the respective enzyme reaction at 450. Mu.L/well.

The results are shown in the following table, with hCD25 monoclonal antibody titers of 1:128000.

Example two

Human CD25 monoclonal antibodies for flow cytometry detection:

The humanized CD25 monoclonal antibody prepared in the first embodiment is used for flow cytometry detection, and the specific method is as follows: 4 centrifuge tubes (1.5 mL), labeled A, B, C, D, were used, PBMC concentration was adjusted to 1X 10 ⁶ per mL, 0.5mL was used per tube, 1mL of PBS was added, 350g was centrifuged for 5min, supernatant was removed, 200. Mu.L of PBS was added to tube A, 100. Mu.L of PBS was added to tube B, then 2. Mu.L of anti-mouse IgG-PE flow antibody (BioLegend) was added, the reaction was stopped by incubation in the dark for 15min, 350g was centrifuged for 5min, supernatant was removed, 200. Mu.L of PBS was added, 2. Mu.L of 7AAD staining solution (BioLegend) was added, incubation was performed for 15min, 100. Mu.L of PBS was added to tube C, 2. Mu.L of anti-hCD25-PE flow antibody (BioLegend) was then added, incubation was performed in the dark for 15min, 350g was centrifuged for 5min, supernatant was removed, 200. Mu.L of PBS was added, 2. Mu.L of 7. Mu.L of PBS was added, incubation was performed in the dark for 15min, and 100. Mu.L of PBS was added, incubation was performed in the dark for 25 min, and incubation was performed in the dark for 100. Mu.L of PBS. Adding 1mLPBS, mixing, centrifuging at 350g for 5min, removing supernatant, and washing for 2 times. 100 mu LPBS re-suspension cells, adding 2 mu L of anti-mouse IgG-PE flow antibody, fully mixing, incubating for 15min in a dark place, terminating the reaction with 1mL of PBS, centrifuging for 5min at 350g, removing the supernatant, adding 200 mu L of PBS to re-suspension cells, adding 2 mu L of 7AAD staining solution (BioLegend), fully mixing, incubating for 15min in a dark place, and detecting 4-tube cells on the machine.

The detection results are shown in fig. 1, and the results show that: the ratio of positive cells of the D tube is 8.9 percent, which is approximately equal to the result of the C tube (8.78 percent), which shows that the hCD25 monoclonal antibody can effectively identify CD25 ⁺ cells and can be used for flow cytometry detection.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The antibody or antigen binding fragment thereof is characterized in that the amino acid sequences of the heavy chain complementarity determining regions CDR-H1, CDR-H2 and CDR-H3 of the antibody or antigen binding fragment thereof are shown in SEQ ID NO.1, and the amino acid sequences of the light chain complementarity determining regions CDR-L1, CDR-L2 and CDR-L3 of the antibody or antigen binding fragment thereof are shown in SEQ ID NO. 2.

2. The antibody or antigen-binding fragment thereof of claim 1, wherein the heavy chain variable region of the antibody or antigen-binding fragment thereof has an amino acid sequence as shown in SEQ ID No.3 or at least 80% similarity to the amino acid sequence as shown in SEQ ID No.3, and the light chain variable region has an amino acid sequence as shown in SEQ ID No.4 or at least 80% similarity to the amino acid sequence as shown in SEQ ID No. 4.

3. The antibody or antigen-binding fragment thereof according to claim 1 or 2, wherein the antibody or antigen-binding fragment thereof is any one selected from the group consisting of monoclonal antibodies, fab ', F (ab') 2, fd, fv, dAb, complementarity determining region fragments, single chain antibodies.

4. A bispecific or multispecific antibody comprising the antibody or antigen-binding fragment thereof of any one of claims 1-3.

5. A nucleic acid molecule encoding the antibody or antigen-binding fragment thereof of any one of claims 1 to 3.

6. A biological material comprising the nucleic acid molecule of claim 5, wherein the biological material is an expression cassette, a vector or a host cell.

7. An antibody conjugate, which is obtained by coupling the antibody or the antigen-binding fragment thereof according to any one of claims 1 to 3 or the bispecific antibody or the multispecific antibody according to claim 4 with a label or a protein, wherein the label is one or more selected from the group consisting of chemiluminescent dye label, enzyme label, biotin label, fluorescent dye label, colloidal gold label and radioactive label.

8. A method of producing an antibody or antigen-binding fragment thereof according to any one of claims 1 to 3, comprising: culturing a host cell capable of expressing the antibody or antigen-binding fragment thereof, and isolating the antibody or antigen-binding fragment thereof.

9. Use of the antibody or antigen binding fragment thereof of any one of claims 1-3 or the bispecific or multispecific antibody of claim 4 or the nucleic acid molecule of claim 5 or the biological material of claim 6 or the antibody conjugate of claim 7 for any one of the following:

(3) Use in detecting the presence or level of cells expressing a human CD25 protein in a sample.

10. A product comprising the antibody or antigen-binding fragment thereof of any one of claims 1-3, or comprising the bispecific or multispecific antibody of claim 4, or comprising the antibody conjugate of claim 7, which product is a detection reagent or pharmaceutical composition.